1. Field
The following description relates to a vacuum cleaner, and more particularly, to a fan motor apparatus for use in an industrial, domestic, or commercial vacuum cleaner, which has a diffuser unit formed therein.
2. Description of the Related Art
A vacuum cleaner generally may have a fan motor apparatus to forcefully draw in external air stream. As the fan motor apparatus starts operating, the vacuum cleaner starts cleaning operation by drawing in external air including foreign matters of the target surface. The foreign matters are then filtered out within the vacuum cleaner, the cleaned air is discharged out of the vacuum cleaner, and the vacuum cleaner completes cleaning operation.
However, as the vacuum cleaner is operated, noise is generated due to operation of the fan motor apparatus and air current discharging out of the fan motor apparatus.
Furthermore, an air stream, which is discharged out of the fan motor apparatus, can include minute matters which are left even after the dust removal operation of the vacuum cleaner. These minute matters may include carbon dusts which are separated from a carbon brush employed in the motor. Problems may arise if such minute dusts or carbon dusts are not completely removed by the discharge filter, and carried along the discharged air stream.
Accordingly, in order to decrease noise and to increase efficiency of removing minute dust at the discharge filter unit, suggestions have been made to distribute an air stream in a uniform manner before discharging it.
For example, U.S. Pat. No. 7,258,714 and U.S. Patent Application Publication No. 2005/0039426 disclose an arrangement including a plurality of vanes along a direction of airflow (“conventional art 1”). Additionally, U.S. Patent Application Publication No. U.S. 2007/0067948 discloses an arrangement of a plurality of holes formed in an outlet of a motor housing (“conventional art 2”), and Korean Patent Publication No. 2006-62145 discloses a fan motor unit having an inlet vertically formed to face a downward direction and a casing having a plurality of air-passing holes in an air discharge portion of the fan motor unit (“conventional art 3”).
Specifically, conventional art 1 suggests that noise generated from an air discharge may be decreased by drawing in airflow inside the vacuum cleaner, which is removed of dust, into the fan motor unit, and distributing the discharged air through a motor housing having a plurality of vanes so that the discharge pressure may be distributed.
However, in the case of conventional art 1, since airflow is drawn through a side of the motor housing to be distributed and discharged, different passages have to be provided to serve as an air inlet and an air outlet. Accordingly, structure becomes complicated, the number of parts required to form airflow passages is increased, and the overall volume is increased.
According to conventional arts 2 and 3, the fan motor unit may be installed in a manner in which the lower portion faces a downward direction. Accordingly, airflow is drawn through the lower portion of the fan motor unit and discharged through the motor housing positioned above the fan motor unit. Conventional arts 2 and 3 may distribute airflow and decrease noise with a plurality of air-passing holes formed in the motor housing.
However, similar to the drawback with conventional art 1, conventional arts 2 and 3 also need separate passages to draw in and discharge out an air flow with respect to the fan motor unit. Accordingly, air passages may become complicated, the number of necessary parts is increased, and the overall size is increased.
Furthermore, according to conventional arts 2 and 3, since it may be necessary to form a passage to draw in airflow in a lower portion of the fan motor unit, the fan motor unit has to be installed at a relatively higher position, causing a vacuum cleaner to have a higher center of mass and subsequently a decreased stability.